tedster - 4:40 pm on Jun 9, 2011 (gmt 0)

Under the normal algo (which is static until manually updated, presumably)

My understanding is that Google's entire algorithm is now dependent on machine learning. Human quality raters give feedback on various SERPs and that creates seed sets of less than optimal rankings. Then the machine-learning program ranges over the data signals that Google collects to learn how those factors could be applied to create a more optimal SERP. When the new machine-proposed algo passes some quality checks, it becomes live.

why do so many people report that their Pandalized rankings are remarkably stable even after making radical changes?

And that is a mystery - although many people have reported incremental gains in traffic during those interim periods.

The challenge we face is being limited to anecdotal reports, for the most part. It's hard to arrive at anything rigorous that way. I know I certainly don't have a big pile of Pandalyzed sites to work on in a scientific way.